The invention relates to a feed device for strip-shaped tire components within a conveying apparatus (servicer) for a tire build-up drum, especially for a belt drum for the assembly of the belt package, whereby successively placed and rolled onto the tire build-up drum are a plurality of plies of different or differently pre-treated, essentially strip-shaped tire components that are bonded to the already applied materials, whereby the conveying apparatus is provided with
a) one or more storage means, preferably a drum storage means, as well as appropriate pertaining feed devices for the tire component, as well as
b) one or more cutting devices associated with the feed devices for cutting the strip-shaped tire component to length,
whereby the conveying apparatus is furthermore provided with one or more conveying lines/conveying paths in which the cut tire components are conveyed to the tire build-up drum.
In the classic manufacture of a new tire with a carcass built-up in a flat manner, the inner liner or inner plate of a tire, and the sidewalls, are first applied to a carcass build-up drum having a horizontal axis of rotation, and are rolled onto the circumference of the drum, as a result of which the still unvulcanized rubber materials are adhered together, as also occurs during the still later applied tire components or tire materials, depending upon need.
Subsequently, especially with truck or commercial vehicle tires, bead-reinforcing profiles are applied, for example so-called xe2x80x9cchafersxe2x80x9d, which can also be provided with textile or metallic load-carrying members, and are conventionally arranged in such a way that in the finished tire at least one carcass ply is disposed between the core and the chafer.
Furthermore, generally one or two carcass plies are applied that are comprised of rubberized textile or metallic load-carrying means. Depending upon need, there then follows the application of shoulder-filling profiles (shoulder pads) that in the finished tire have the function of providing a compensation between the belt contour, which is also flat at its edges, and the more greatly curved carcass contour at the belt edges.
Subsequently, with the aid of a carcass carrying and core-centering device, the bead cores, which are conventionally already provided with core sliders, are pushed and positioned over the drum. Bead core and core slider (apex) are hereby already present as a prefabricated unit that is produced on a separate drum (extensible drum) and are placed as prefabricated rings from the side over the plies that are already present on the tire build-up drum.
When the build-up drum is subsequently expanded, the prefabricated bead cores and the flat carcass are pressed radially against one another, so that the inner surfaces of the bead cores are adhered and connected with the outer carcass surface.
The drum is thereafter drawn together to a smaller diameter, and the carcass with the set bead coresxe2x80x94again with the aid of the carcass carrying and core centering devicexe2x80x94is withdrawn from the drum and transferred to the expansion drum.
Parallel to the fabrication of the carcass, applied to a belt build-up drum in the separate belt manufacturing line are the belt plies, which in general are two or three, and with the manufacture of truck tires generally four rubberized steel cord plies; if desired, one or two plies of a nylon band can be provided. Belt cushion strips can be disposed between the individual belt plies. Finally, applied to this belt structure is the tread strip, which can be provided with an underplate.
A movable belt carrying device for accommodating the prefabricated belt package transports the thus resulting belt/tread strip structure to the expanding drum having the already centered, fixed and pre-expanded tire carcass, and positions this structure over the tire carcass.
This is now completely expanded and joined with the belt package, whereby with the expansion (bulging) of the carcass, the folding process is also effected, according to which the carcass ply ends are folded about the bead cores and the side portions are folded up. This process is carried out with the aid of bellows, whereby a center bellows expands the central portion of the carcass and side expansion bellows, in other words expansion bellows, which engage axially beyond the set cores, are used for folding up the side portions, possibly aided by presser rings (pushers), etc.
After the expansion and the connection of the carcass with the belt package, the belt carrying device is removed and the tread strip is rolled on together with the belt package.
After the deflating or release of the expansion bellows, the fabricated green tire is then removed from the expansion drum by further transfer devices and is vulcanized in an appropriate vulcanization mold, where it thus obtains its final shape with a molded tread strip profile, possibly also with sidewalls that contain writing and/or decoration.
Especially at the stations of the tire manufacturing, i.e. the manufacturing plant, at which a plurality of strip-shaped tire components are placed directly or at successive intervals on a tire build-up drum, in other words, for example, during the placement of four successive rubberized belt plies upon the belt build-up drum of a truck tire manufacturing, to facilitate and automate the manufacturing process so-called conveying apparatus or xe2x80x9cservicersxe2x80x9d are operated which, generally with a plurality of transport and cutting devices, transport the strip-shaped tire components from a plurality of storage means, cut them to length and at prescribed angles, transport them to the build-up drum, and there place them upon the already applied materials or components.
As storage means for strip-shaped tire components, these days generally coil or drum storage means/storage cassettes or modules are used in which the material needed for the tire components is placed in rolls and can be withdrawn over appropriate feed paths and via feed devices by means of the transport devices of the conveying apparatus. The storage means are hereby disposed directly on the conveying apparatus. The roller accommodating means/the roller bearing is generally driven in order to avoid tension on the material during withdrawal. In this connection, there are generally provided between the storage means and the transport devices compensation loops of the material that also serve this purpose and compensate for differences in speed between the roller drive and the transport device.
As a consequence of the number of storage means, or the number of the successively to be applied strip-shaped tire components, a corresponding number of required feed devices result within the feed path for the tire component. Thus, with a conveying apparatus for four rubberized belt plies upon the belt build-up drum of a truck tire manufacturing, in conformity with the four storage means for variously built-up belt ply materials, four feed devices are also required for the tire component.
At or under the cutting devices that are associated with the feed devices, transport lines begin that, from the spatially differently arranged feed devices/cutting devices, all must lead to the same destination, namely to the tire build-up drum, or to the point of application for the tire components that is disposed on the periphery of the tire build-up drum.
In this connection, with the tire components of still unvulcanized rubber materials used for the tire manufacture, for example with the belt plies that comprise rubberized load-carrying means, there exists the requirement for conveying the tire component without stretching, bending and other deformations, in other words in as flat a support as possible on a planar surface, to the tire build-up drum. The transport lines should therefore contain to the extent possible no bends or curves for guiding the tire components, and must have transport devices that convey the tire component in as flat a support as possible and exclusively in a linear direction from the locally/spatially separated feed devices to a point of application upon the tire build-up drum that is the same for all tire components.
The state of the art resolution of this problem is that the transport devices that are associated with each transport line are embodied, generally in three parts, as circulating/continuous conveyor belts having an upper run that is as planar as possible. In this three-part construction, each of the transport devices, starting from the feed device, in other words from the introduction of the tire component from the storage means, has a transport device, associated with the feed device, for the withdrawal of the tire component from a storage means and for the positioning of the tire component in or under a cutting device (feed band), a further transport device for transporting the cut tire component from the cutting position to the tire build-up drum (drum feed band), as well as a transport device for the placement of the cut tire component upon the built-up drum (transfer band).
In this connection, the feed band that is associated with the feed device is only relatively short, is stationary and overlaps a region of the transport line from the introduction of the tire component that is customarily effected via guiding and conducting devices that are embodied as roller systems, up to the cutting device, in which on a rail that slides on a feed band the tire component is cut with a roller-type blade.
The subsequent transport device for the transport of the cut tire component out of the cutting position to the tire build-up drum, in other words the drum-supply band or conveyor, onto which the tire component that is cut at one end is subsequently placed, has such a length that it can accommodate the entire length of the tire component, in this case a belt ply, that is prescribed essentially by the circumference of the tire. After the necessary belt length is achieved, in the cutting device the second end cut of the tire component is then carried out whereafter the cut tire component is transferred completely to the drum-supply conveyor.
In this connection, the drum-supply conveyor is movable and/or pivotable in its entirety, i.e. with drive devices, band rollers and guide plates for the support of the upper run, and can be moved from a rear cutting and support position in which the drum-supply conveyor is loaded, i.e. in which the cut tire component is fed to the drum-supply conveyor, into an advanced support position in which it is unloaded, i.e. in which the tire component is applied to the tire build-up drum.
In this connection, the drum-supply conveyor, in the rear cutting and support position, is in line with and at the same height as the feed conveyor, so that the tire component can be transferred from the stationary feed conveyor that is disposed within the conveying apparatus.
In the advanced support position, the drum-supply conveyor is then in line with the tire build-up drum and at the same height as the point of application, so that at that location the tire component can be transferred to the tire build-up drum and can be wound thereon.
Thus, for the transfer of the tire component to the tire build-up drum, the drum-supply conveyor moves spatially transverse, generally with the aid of various parallelogram guides, pivot mechanisms and lifting mechanisms, whereby during this movement of the drum-supply conveyor, the (transport) conveyor as such with the tire component placed thereon generally does not move, in other words does not circulate. The circulation of the drum-supply conveyor is again restarted for the transfer of the tire component to the tire build-up drum.
The multiple transfer from one conveyor belt to the following is in this connection a drawback either with regard to the release of material tensions or also produces stretching or bunching in the material, which can be problematic during the later application to the tire build-up drum.
Since with many conventional conveyors the point of application is located at the lower apex of the tire build-up drum, for the transfer of the tire component to the tire build-up drum, where the tire component must be guided to the periphery of the drum in a tangential and overshot manner, it is necessary to provide a short transfer conveyor in the feed line as a further transport device. This is necessary since the drum-supply conveyor can tangentially reach the upper apex of the tire build-up drum with only its lower run; the tire component is, however, flushly supported on the upper run.
Such a transfer conveyor is embodied as a further conveyor belt that adjoins that end region of the drum-supply conveyor that faces the tire build-up drum, and in this connection is somewhat higher than the drum-supply conveyor and overlaps the latter slightly in its end region. The gap that then remains in this end region between the upper run of the drum-supply conveyor and the lower run of the transfer belt is adjustable and essentially corresponds to the thickness of the tire component that is to be applied.
In this connection, the transfer belt is generally also secured to the frame and guide construction of the drum-supply conveyor, and is movable therewith from the rear cutting and support position into the advanced support position.
In the advanced support position, the lower run of the transfer belt is now disposed in the region of the upper apex of the tire build-up drum, i.e. at the point of application, again with a small spacing or gap and essentially tangential thereto. If in this position the drum-supply conveyor and the transfer belt are driven in a circulating manner at the same speed, the tire component that is now advanced on the upper run of the drum-supply conveyor, in the region of the gap between the upper run of the drum-supply conveyor and the lower run of the transfer belt, has its upper surface, due to its natural tackiness, adhered to the lower run of the short transfer belt and thus is tangentially guided in a xe2x80x9csuspendedxe2x80x9d manner to the tire build-up drum, where it is applied. The adhesion to the lower run of the transfer belt can in this connection be aided by, for example, underpressure devices.
During a conveying process, the point of application is also disposed in the lower region of the tire build-up drum, whereby for the transfer of the tire component to the tire build-up drum the drum-supply conveyor can then also be used directly, and the tire component is guided tangentially and in an undershot manner to the periphery of the drum. The direction of rotation of the tire build-up drum, and the support of the tire component upon the drum-supply conveyor, must in this connection of course be appropriately adapted to one another.
For the placement of four rubberized belt plies upon the belt build-up drum of a truck tire manufacturing, there thus results four feed lines and following them respectively four transport lines, all of which must be provided with appropriate transport and cutting devices. Thus, in addition to the already described problems due to the multiple transfers, there of course results an extremely complex structural configuration of the feed and conveying device and a space requirement that considerably exceeds that for the actual tire build-up drum in addition to the auxiliary units. Conveying apparatus for such a multiple support can, in this connection, be provided with feed and transport lines that are disposed parallel to one another, or that are disposed in pairs over one another. The expense for maintenance or repair rises overproportionally in conformity with the complexity of such a layout, so that on the whole an economical manner of operation can be achieved only with very large quantities on a permanent basis.
It is therefore an object of the invention to provide a feed device that permits a number of transport devices, and hence the transfer within a conveying apparatus, to be reduced, which in this connection ensures a support of the tire component that is as planar, linear and free of tension as possible, which can be produced and operated in an economical manner, and the construction of which is easy to integrate into existing tire manufacturing plants.
The object is realized by the features of the main claim. Advantageous further developments are contained in the dependent claims.
Herewith, within a respective conveying line, the conveying device for the withdrawal of the tire component from the storage means and for the positioning of the tire component in or under the cutting device, and the conveying device for the transport for the cut tire component to the tire build-up drum, are embodied as an interconnected one-piece transport system, preferably as a circulating/continuous conveyor belt, whereby the one-piece transport system is movable and/or pivotable within the conveying apparatus between a rear-cutting and support position, in which the cut tire component is supplied to the one-piece transport system, and an advanced support position in which the tire component is applied to the tire build-up drum, whereby the feed devices are disposed and/or movable relative to the one-piece transport system in such a way that in its rear cutting and support position the one-piece transport system is respectively in operative connection with a cutting device, and whereby the feed device and the one-piece transport system are provided with holding or fixing devices for the tire component which are movable to the tire component and are disposed in the region of the cutting device, and which during the movement and/or pivoting of the one-piece transport system temporarily fix in position not only the tire component that is withdrawn from the storage means and that after the cutting remains on the side of the storage means relative to the line of cut, but also the tire component already transferred to the one-piece transport system.
As a consequence of such a configuration of the feed device, it is possible to hold the tire component that remains on the side of the storage means after the cut in position without it being necessary to have a support on one of the conveyor belts. This enables a construction of the conveying apparatus with which the feed belt and the drum-supply conveyor are embodied as a one-piece transport system that is movable between a rear cutting and support position and an advanced support position and is thus moved into the region of the feed device only for the loading or unloading of the tire component, and in this region carries the entering tire component.
Thus, a separate feed belt is no longer necessary, as a result of which in each conveying line one of the critical material transfers from one conveyor belt to the following is eliminated.
This furthermore results in the important advantage that a drum-supply conveyor, in other words a one-piece transport system, can be combined with a plurality of feed devices, whereafter the drum-supply conveyor can then be moved into various rear cutting and support positions, where various tire components, in other words for example different belt plies can then be cut and applied. Since in this case only one one-piece transport device, namely the drum-supply conveyor, can be used for a plurality of feed devices, the critical transfer locations are further drastically reduced.
The feed device is advantageously embodied in such a way that for the tire component that after the cut remains on the side of the storage means relative to the line of cut, the holding or fixing device, and the cutting device, are disposed within a lifting device that is associated with the feed device, with which lifting device the holding or fixing device, the cutting device, and the temporarily fixed tire component are movable into a position above the plane of the upper run of the circulating/continuous conveyor belt of the one-piece transport system.
As a result of such a configuration, the introduction of the drum-supply conveyor into the rear cutting and support position is facilitated to the extent that the guides, the drive mechanisms, and the pivot mechanisms for achieving this position can be embodied within normal tolerances, since during the introduction into the rear cutting and support position the holding or fixing device and the cutting device can be moved with the tire component into a reliable and spaced lifting position from which the tire component and the mentioned devices can then be lowered onto the drum-supply conveyor that is disposed in the rear cutting and support position.
In particular with the use of tire components that are provided with metallic load carrying means, in other words, for example, with rubberized belt plies, pursuant to one advantageous embodiment, the holding or fixing device for the tire component that after the cut remains on the side of the storage means relative to the line of cut comprises a pressure plate, which is disposed above the tire component, and a magnetic plate that is disposed above the pressure plate and is movable to the pressure plate or the tire component, whereby the magnetic plate fixes the tire component on the pressure plate.
Such magnetic plates can comprise permanent magnets, so that it is not necessary to have an additional supply of electrical energy; the magnetic plates can also be provided with electro magnets that can be switched on.
Pursuant to a further advantageous embodiment, for the tire component that after the cut remains on the side of the storage means relative to the line of cut, the holding or fixing device comprises an apertured or air-permeable pressure plate that is disposed above the tire component and is movable to the tire component, and a vacuum device that is disposed above the pressure plate and could be movable to the pressure plate or the tire component, whereby the vacuum device fixes the tire component on the pressure plate.
With such a device, it is also easy to fix tire components that contain no metallic inserts, in other words, for example, textile-reinforced plies or rubber plies without any reinforcement.
For such types of tire components that can receive the distributed, point-type holding fixture without influencing the further processing, pursuant to a further advantageous embodiment, for the tire component that after the cut remains on the side of the storage means relative to the line of cut, the holding or fixing device comprises a plurality of needles or rods that are disposed on a base plate and extend through the one-piece transport system, whereby the base plate, which is provided with needles, is disposed below the one-piece transport system.
In this connection, with a sufficient number of needles, one achieves only a minimal penetration of the needle points into the material, whereby the thereby resulting, small impressions are again closed by the later vulcanization.
The drum-supply conveyor can, for example, in this connection be embodied in such a way that it comprises a plurality of narrow conveyor belts that are disposed next to one another, so that the needles extend through into the intermediate spaces into the one-piece transport system and can support the tire component.
The already described advantages of a holding or fixing by magnetic force for tire components having metallic load-carrying means can also result in a further embodiment according to which, for the tire component already transferred to the one-piece transport system, the holding or fixing device is embodied as a magnetic plate that is disposed between the upper run and the lower run of the one-piece transport system, which is embodied as a circulating/continuous conveyor belt and is movable to the upper run or the tire component.
As a consequence of the arrangement of such a magnetic plate between the upper run and the lower run of the one-piece transport system, and in the region of the cutting device, i.e. in the rear portion of the drum-supply conveyor, which upon reaching the rear cutting end support position is disposed below or within the feed device, it is also possible here in a relatively straightforward manner to effect a fixing of the tire component, especially during the cutting process.
With the feeding of tire components that contain no metallic load-carrying means, in other words, for example, with textile reinforced rubberized components, as already with the holding or fixing device within the lifting device, pursuant to an advantageous embodiment for the tire component already transferred to the one-piece transport system, the holding or fixing device is embodied as a vacuum device that is disposed between the upper run and the lower run of the one-piece transport system, which is embodied as a circulating/continuous and possibly air-permeable conveyor belt, and could be movable to the upper run or to the tire component.
Pursuant to a further advantageous embodiment, the feed device is provided with a guiding and conducting device for the tire component withdrawn from the storage means that is movable with the lifting device and is embodied as a roller system.
As a consequence of such a guiding and conducting device, which is connected with the lifting device, one already avoids during the introduction of the tire component undesirable stretching and tensioning that could result during a frequent movement or alteration of the curvature of the entering tire component.